Live events, for example, sports games, can be transmitted over the Internet for real-time viewing by end users using, for example, the HLS (HyperTexTProtocol (HTTP) Live Streaming) protocol. Details of the HLS protocol are described in the IETF Internet Draft (Individual Submission) “HTTP Live Streaming” version 19, dated Apr. 4, 2016, (draft-pantos-http-live-streaming-19.txt) which is incorporated by reference herein in its entirety. HLS is an adaptive streaming protocol that works by breaking an overall stream into a sequence of small HTTP-based downloads, referred to as “media segments,” and which may also be referred to as “slices.” Each slice provides a small chunk of a potentially unbounded transport stream. Each end user device can include a client (e.g., a browser-based application program) that establishes a unique streaming session with a streaming web server. Each HLS client may select from a number of different “variant streams” (or “sub-streams”) containing the same presentation encoded at a variety of data rates. This allows a client to request, both in initiating and maintaining a streaming session, material at an appropriate resolution for, or according to the capabilities of, a playback device on which it will be reproduced. Playback devices can include, for example, hand-held devices, laptop computers, and large-screen displays. As an example, a live streaming provider might operate a plurality of HLS live streaming servers providing the video portion of a presentation encoded at eight different resolutions, for example, 320×180, 512×288, 768×432 . . . 1280×720.
As described above, each client accessing a live streaming event establishes a unique streaming session with a streaming web server, and each streaming session is a separate unicast streaming session. Therefore, in live streaming events with a large population of viewers, the result can be a correspondingly large number of unicast streaming sessions traveling through the Internet, and through Internet Service Provider (ISP) interfaces. In addition, a large number of viewers access live streaming events through VSAT (very small aperture terminal) satellite distribution systems. The conventional HLS protocol establishment of a unique unicast streaming session with each client can place a very heavy load on conventional VSAT systems.